7 minute read
troubleshooting procedure
Troubleshooting
Troubleshooting procedure
Step Inspection
1 Inspect coolant temperature l Is coolant warmed up sufficiently?
*2 Verify whether malfunction is in air mix
actuator (+5v signal) system or elsewhere.
l Turn ignition switch to on position. l Measure the voltage at terminal c (+5v signal) of air mix actuator. l Is voltage approximately equivalent to +5v?
*3 Inspect air mix actuator for continuity. l Disconnect air mix actuator connector
l Measure the voltage at terminal c (+5v signal) of air mix actuator l Is voltage approximately equivalent to 5v? Yes Inspect air mix actuator, then go to step 21.
No Go to next step.
*4 Inspect continuity of wiring harness between
rear climate control unit and air mix actuator.
l Turn ignition switch to lock position. l Disconnect rear climate control connector.
l Is there continuity between terminal c (+5v signal) of air mix actuator conduct and terminal h of rear climate control unit? Yes Go to next step.
No Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
Action
Yes Go to next step.
No Warm up engine to normal operation temperature, then go to step 21.
Yes Go to step 6.
No Go to next step.
*5 Verify whether malfunction is in wiring
harness (short circuit to ground between rear climate control unit and air mix actuator) or in rear climate control unit.
l Is there continuity between terminal c (+5v signal) of air mix actuator and ground?
*6 Inspect continuity of wiring harness between
rear climate control unit and air mix actuator.
l Turn ignition switch to lock position. l Disconnect connectors of rear climate control unit from air mix actuator.
l Is there continuity between terminal f of rear climate control unit and terminal e of air mix actuator? Yes Go to next step.
No Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
Yes Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
No Replace rear climate control unit, go to step 21.
*7 Inspect wiring harness between rear climate Yes Repair wiring harness between rear
U-28
Troubleshotting
Step Inspection control unit and air mix actuator to determine whether it is short to ground.
l Is there continuity between terminal e (voltage divider signal) of air mix actuator and ground?
*8 Inspect wiring harness between rear climate
control unit and air mix actuator for short with b+ (positive battery voltage)
l Turn ignition switch to on position. l Measure wiring harness-side voltage of terminal e (voltage divider input signal) of air mix actuator.
l Is voltage approximately equivalent to b+ (positive battery voltage)? Yes Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
No Go to next step.
*9 Inspect continuity of wiring harness between
rear climate control unit and air mix actuator.
l Is circuit between terminal e of rear climate control unit and terminal a of air mix actuator close?
*10 Inspect wiring harness between rear climate
control unit and air mix actuator to determine whether it is short to ground.
l Is there continuity between terminal e of rear climate control unit connector and ground?
*11 Inspect wiring harness between rear climate
control unit and air mix actuator to determine whether it is short to b+ (positive battery voltage)
l Turn ignition switch to on position. l Measure voltage at terminal e of rear climate control unit connector.
l Is voltage approximately equivalent to b+ (positive battery voltage)? Yes Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
No Go to next step.
Action
climate control unit and air mix actuator, and then go to step 21.
No Go to next step.
Yes Go to next step.
No Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
Yes Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
No Go to next step.
U-29
Troubleshooting
Step Inspection
*12 Inspect continuity of wiring harness between
rear climate control unit and air mix actuator.
l Is there continuity between the following terminals of rear climate control connector and terminals (motor driving signal) of air mix actuator?
— Terminal a — Terminal g — Terminal b
— Terminal f Yes Go to next step.
No Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
*13 Inspect wiring harness between rear climate
control unit and air mix actuator to determine whether it is short to ground.
l Is there continuity between following terminals of rear climate control unit and ground? — Terminal a
— Terminal b Yes Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
No Go to next step.
*14 Inspect wiring harness between rear climate
control unit and air mix actuator to determine whether it is short to b+ (positive battery voltage)
l Turn ignition switch to on position. l Measure wiring harness side voltage of following air mix connectors. — Terminal a
— Terminal g — Terminal b
— Terminal f l Is voltage approximately equivalent to b+ (positive battery voltage)? Yes Repair wiring harness between rear climate control unit and air mix actuator, go to step 21.
No Go to next step.
15 Inspect air mix actuator of rear a/c unit. l Remove the actuator. l Inspect air mix links and rockers of rear a/c unit. — Is there grease on links and rockers? — Are links and rockers firmly installed at proper position? l Are all above items normal?
Action
Yes Go to next step.
No Apply grease or install links and rockers firmly at proper positions, go to step 21.
U-30
Troubleshotting
Step Inspection
16 Verify whether malfunction is in air mix
actuator or elsewhere.
l Turn ignition switch to on position. l Set rear main fan switch at 3rd position. l Does temperature of air blown out change easily with air mix rocker operated manually?
17 Inspect air mix actuator. l Inspect air mix actuator. (see u-30, air mix actuator inspection) l Is it normal?
18 Inspect rear a/c unit l Is rear a/c unit air mix control valve clogged with foreign material?
19 Inspect reara/c unit’s air mix control valve. l Inspect rear a/c unit’s air mix control valve for the following items. — Is there any damage or crack with the air mix control valve?
— Is air mix control valve firmly installed at proper position? l Are all above items normal? Yes Go to next step.
No Replace air mixing control valve or install it in proper position firmly, go to step 21.
20 Inspect heater pipeline l Inspect heater pipeline for the following items.
— Is there any damage or crack with the heater pipeline?
— Is there any coolant leakage with the heater pipeline joints? — Is there loose with the heater pipeline joints? — Is there any leakage with connection between the heater pipeline and the rear a/c unit?
l Are all above items normal? Yes Replace rear climate control unit and turn to next step. If the heater pipeline is loose, tighten to specified torque.
No Repair or replace heater pipeline, go to next step.
21 Verify whether malfunction symptom occurs
after repair.
l Does rear climate control unit operate well at different temperature?
Action
Yes Go to next step.
No Go to step 18.
Yes Go to next step.
No Replace air mix actuator, go to step 21.
Yes Remove obstruction, go to step 21.
No Go to next step.
Yes Troubleshooting completed. Explain causes to customer.
No Recheck malfunction symptoms, repeat from step 1 if malfunction reoccurs.
U-31
X. Air is not cold as specified.
Troubleshooting
10 Air is not cold as specified.
Malfunction symptom
Possible causes
Magnetic clutch operates, but malfunction is in a/c unit.
Drive belt malfunction. Step 1 l Malfunction in blower assembly, rear a/c unit and/or condenser. Steps 4, 5 l Malfunction in reservoir/drier, expansion valve (valve closes too much). Step 8 l Malfunction in refrigerant pipelines. Steps 9, 10 l Malfunction in refrigerant pipeline joints. Steps 1, 2, 12 l A/c compressor malfunction, insufficient compressor oil. Steps 14, 15 l Too much compressor oil, malfunction in expansion valve, or a/c unit air mix link fault. Steps 16-18
Troubleshooting procedure
Step Inspection
1 Inspect drive belt l Inspect drive belt — Gy: (see b-1 adjustment of drive belt) l Is it normal?
Action
Yes Go to next step.
No Replace driver belt, go to step 19.
2 Inspect cooling system performance l Test refrigerant system performance. (refer to u-7 performance test of refrigeration system) l Is operation normal?
3 Verify whether malfunction in air intake of
a/c unit and condenser or elsewhere.
l Are pressures of refrigerant pipeline at high and low pressure side excessive high?
4 Inspect a/c unit air intake port. l Is a/c unit air intake port clogged? Yes Operation is normal. (recheck malfunction symptoms)
No Go to next step.
Yes Go to next step.
No Go to step 6.
Yes Remove obstruction, and then go to step 19. (if air does not reach evaporator within cooling unit, heat exchange does not occur and refrigerant pressure becomes high. Therefore, removal of obstruction is required.)
No Go to next step.
